The Falconer by Elizabeth May

Hunt the fae. Cage the monsters. Guard the prison.

Aileana Kameron is no ordinary Victorian debutante. By day, she navigates the glittering society of 1844 Edinburgh. By night, she battles the deadly fae that threaten humanity. For centuries, her family has upheld a sacred duty: ensuring the ancient, magical prison beneath the city stays sealed.
But cracks are forming in the barrier. The monsters she once hunted now hunt her, and the fate of the world teeters on the edge. To stand a chance, Aileana must turn to Kiaran MacKay, a breathtakingly dangerous fae assassin whose dark past hides secrets as sharp as his blades.
Their alliance is as treacherous as it is intoxicating. Passion ignites between them, as fiery as the battles raging in Edinburgh’s streets. But every choice comes with a cost, and as the death toll rises, Aileana is forced to confront a harrowing question:
How far is she willing to go to save her city, her loved ones – and herself?
Because if she fails, the fae will break free. And once they do, nothing will stop their vengeance.